So E1 indicates a loss of communication to one or more of the units in that zone. I presume you have a single A/C Heat Pump but let me know if you have another. It could be the furnace controller has quit or it could be an issue with the heat pump.
You might try to reset it a couple more times you might get lucky, press mode and zone at the same time and the display will say IniT and list all available zones. Release the buttons and press On/Off .
If that does not help, we will have to go into it deeper.
First make sure the
12V power is good to the Heat Pump. Are the batteries fully charged and showing at least 12.7 Volts?
1. Check the CCC2 Unit communications connections, unplug them and replug them
2. check the furnace controller board led to see if there is a fault there
3. Disconnect the furnace from the Heat Pump Control board to see if the furnace has a short.
then it gets more complicated as it could be another instrument connection like the temperature sensors etc.
Each one of the above steps are not trivial either. the communication connectors are inside the return air plenum behind the return screens. the other is in the wall behind the thermostat.
You can see the furnace diagnostic led after removing the outside furnace cover. The gas exhaust pipe first has to be removed.
Linear Mode
